MUTATON mayrnan Flashcards
mutation
a change in gene or chromosome structure
mutant
an individual showing or carrying a mutation
mutagen
a chemical causing a mutation
two types of mutation
gene mutation - single gene
chromosome mutation-single chromosome or set of chromosome
mutation characteristics
occur at random
spontaneous
rare
\increses by chemicals or radiation
deletion and insertion leads to
frame shift
frame shift
insertions and deletions cause a shift in the whole sequence of bases and all the codons after that point are altered
substiituion
will only alter one codon
this results in only one amino acid in the protein being charged
this is known as point mutation
beneficial mutations
selective advantage
out compete those in the pop without the advatgous characteristic
this is the deriving force behind natural selection
silent
when mutation in non coding part
based triplet changed but no effect on amino acid coded for
sickle cell anaemia
when the 4 polypeptide chains curl up they form a specific 3d shape
if the o2 level in blood falls ,valine forms bonds with themselves that stick haemoglobin molecules;es together producing long chains of stuck together haemoglobin molecules , the abc is pulled out of its usual biconcave shape
natural selection
evolution of popultiona
sexually rep po shows gen diverity
random mutations can result in new alleles of a gene appearing
if the new allele benefits the organism this could lead to inc repoructuve success
advantageous allele is inherited by the next gen
new allele inc frequency
leads to species being better adapted
antibiotic resistance
directional selecton
some bacteria carry allele whc=ich gives resistance to certain antibiotic c
those don’t carry oxalate will be killed by antibiotic eating resistant strain to reporidyce and pass on the allele for resistance to next gen more drictribution curve to the right as the mean moves towards higher resistance.
